tar_download.py

import os
import sys
import tarfile
try:
    from urllib import urlretrieve
except ImportError:
    from urllib.request import urlretrieve

def file_name_from_url(url, directory=None):
    file_name = url.split('/')[-1]
    if directory:
        file_name = os.path.join(directory, file_name)
    return file_name

def check_file_exists(url, directory=None, skipFound=True):
    file_name = file_name_from_url(url, directory)
    if os.path.exists(file_name):
        if skipFound:
            print("File already found: {}, skipping download of {}".format(
                file_name, url))
        return True
    return False

def download_tar(url, directory=None, skipFound=True):
    if skipFound and check_file_exists(url, directory, skipFound):
        return

    if not os.path.exists(directory):
        os.makedirs(directory)

    file_name = file_name_from_url(url, directory)
    print("Downloading {} to {}".format(url, file_name))
    sys.stdout.flush()
    urlretrieve(url, file_name)

def extract_contents(file_name, destination='.'):
    if not os.path.exists(destination):
        os.makedirs(destination)

    print("Extracting {} to {}".format(file_name, destination))
    sys.stdout.flush()
    tar = tarfile.open(file_name)
    tar.extractall(destination)
    tar.close()

def download_and_extract(url, directory=None, skipFound=True):
    if skipFound and check_file_exists(url, directory, skipFound):
        return

    download_tar(url, directory)
    extract_contents(file_name_from_url(url, directory), directory)